CVE-2026-105798 — SimpleChat is a secure AI conversation application with personal and group workspaces for…¶
Key facts
CVE-2026-105798 is a High (8.7) vulnerability: SimpleChat is a secure AI conversation application with personal and group workspaces for…. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-105798 |
| Severity | High (8.7) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-105798/ |
Details¶
English | 한국어
Description¶
SimpleChat is a secure AI conversation application with personal and group workspaces for document-grounded interactions. Prior to 0.261.029, POST /api/group_documents/upload stores an attacker-controlled group document filename that group_workspaces.html later interpolates into inline Share event handlers. The escapeGroupHtml function leaves apostrophes unchanged, while escapeHtml produces an HTML entity that the browser decodes before JavaScript evaluation, so either path permits the filename to terminate the handler string. An authenticated group Owner, Admin, or DocumentManager can persist script that executes in the SimpleChat origin when another group member clicks Share, allowing access to victim-visible data and actions with the victim session. This issue is fixed in version 0.261.029.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-105798 |
| Type | XSS |
| CVSS Score | 8.7 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-105798/poc.py
Usage¶
# Run PoC against target
python3 poc.py --target <TARGET_URL>
# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>
⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.
Test Lab¶
This repository includes a Docker-based test environment with both vulnerable and patched applications.
Quick Start¶
# Clone and navigate to CVE directory
cd CVE-2026-105798
# Start both applications
docker-compose up -d
# Run tests
./run-tests.sh # Linux/Mac
./run-tests.ps1 # Windows PowerShell
Application Endpoints¶
| Application | URL | Status |
|---|---|---|
| Vulnerable App | http://localhost:8080 | Shows vulnerability |
| Patched App | http://localhost:8081 | Demonstrates fix |
Directory Structure¶
├── README.md # English documentation
├── README_KO.md # Korean documentation
├── poc.py # PoC detection script
├── docker-compose.yml # Container orchestration
├── run-tests.sh # Linux/Mac test runner
├── run-tests.ps1 # Windows test runner
├── vulnerable-app/ # Vulnerable version
│ ├── app.py
│ ├── Dockerfile
│ └── requirements.txt
└── patched-app/ # Fixed version
├── app.py
├── Dockerfile
└── requirements.txt
References¶
- https://github.com/microsoft/simplechat/commit/537a259eb048b8f6d1c94193fa0c9683ab0bace9
- https://github.com/microsoft/simplechat/security/advisories/GHSA-qwcw-r653-j8c6
- https://github.com/microsoft/simplechat/security/advisories/GHSA-qwcw-r653-j8c6
Generated by PoC Generator on 2026-10-08T22:05:31.220369319
Frequently asked questions¶
What is CVE-2026-105798?¶
CVE-2026-105798 is a High (8.7) vulnerability: SimpleChat is a secure AI conversation application with personal and group workspaces for…. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-105798?¶
Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.
How do I block or mitigate CVE-2026-105798?¶
Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.
For authorized security testing and research only. See the full source and NVD record.